866555449 has 2 divisors, whose sum is σ = 866555450. Its totient is φ = 866555448.

The previous prime is 866555381. The next prime is 866555471. The reversal of 866555449 is 944555668.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 464833600 + 401721849 = 21560^2 + 20043^2 .

It is a cyclic number.

It is not a de Polignac number, because 866555449 - 2⁹ = 866554937 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 866555396 and 866555405.

It is not a weakly prime, because it can be changed into another prime (866555489) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433277724 + 433277725.

It is an arithmetic number, because the mean of its divisors is an integer number (433277725).

Almost surely, 2^866555449 is an apocalyptic number.

It is an amenable number.

866555449 is a deficient number, since it is larger than the sum of its proper divisors (1).

866555449 is an equidigital number, since it uses as much as digits as its factorization.

866555449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184000, while the sum is 52.

The square root of 866555449 is about 29437.3138890083. The cubic root of 866555449 is about 953.3787167527.

The spelling of 866555449 in words is "eight hundred sixty-six million, five hundred fifty-five thousand, four hundred forty-nine".